History is what happened before, but it can help us to find solutions that take care of issues in the present. Thing is, we as mankind did not really change that much over the course of time and we make either the same or similar mistakes (for example in politics, international affairs, etc) that people did back in the day. Selling your history college textbooks to us is the best way to get fast money.
Though history offers solutions to the problems of the present, we often just ignore them for some reason or the other. Problem is, you can’t really efficiently improve the present if you don’t keep track of what kind of mistakes were made in the past. This goes to prove the old adage: “Those who don’t know history are doomed to repeat it”.
History also clearly shows that things change over the course of time and we need to make decisions with that in mind. That may help with solving current conflicts for the long run. But again, we (politicians and authorities) often than not choose to ignore the lessons of the past and strongly resembles shooting oneself in the foot.
You want to sell your history textbooks so that you can both get cash for your hardly ever (if at all) used books and help other people with getting to know what happens in the past and how they can learn their lesson based on the obtained historical data. Tough history is useful for people from all walks of life, it makes most sense for politicians and similar careers.